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For the analysis of edible oils, saponification is well known as a useful method for eliminating oil matrices. The conventional approach is conducted with alcoholic alkali; it consumes a large volume of organic solvents and impedes the retrieval of analytes by microextraction. In this study, a low-organic-solvent-consuming method has been developed for the analysis of benzo[a]pyrene in edible oils by high-performance liquid chromatography with fluorescence detection. Sample treatment involves aqueous alkaline saponification, assisted by a phase-transfer catalyst, and selective in situ extraction of the analyte with a supramolecular solvent. Comparison of the chromatograms of the oil extracts obtained by different microextraction methods showed that the supramolecular solvent has a better clean-up effect for the unsaponifiable matter from oil matrices. The method offered excellent linearity over a range of 0.03– 5.0 ng mL−1 (r > 0.999). Recovery rates varied from 94 to 102% (RSDs

A simple and rapid method based on magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC–MS/MS) was used for the determination of 15 sulfonamides from milk samples. The extraction and cleanup used a graphene oxide-based magnetic nanocomposite (Fe3O4@GO) as an adsorbent. Various experimental parameters that could affect the extraction efficiencies, such as the amount of Fe3O4@GO, the extraction time, the ionic strength of sample solution, and the type of eluent, were investigated. Under optimized experimental conditions, good linearity was observed in the range of 2.0 to 100.0 μg L−1 for all of the analytes, with correlation coefficients (R2) ranging from 0.994 to 0.999. The limits of detection for the method ranged between 0.02 and 0.13 μg L−1. Mean values of the relative standard deviation of intraday and interday precision ranging from 1.0 to 7.3 % and from 1.7 to 8.1 % were obtained, respectively. The average recoveries were between 73.4 and 97.4 % at three different spiked levels. It was confirmed that the Fe3O4@GO nanocomposite was an effective MSPE material for use in sulfonamide analyses in milk samples.

Edible oil is easily contaminated with phthalic acid esters (PAEs). Conventional procedures to analyze individual PAEs require very rigorous experimental conditions that are extremely labor-intensive due to significant procedural contaminations generated by the ubiquitous presence of PAEs in the laboratory environment. In this study, a rapid screening method for PAEs in edible oil was successfully developed. Using a phase-transfer catalyst (terabutylammonium bromide) during oil/water biphasic base hydrolysis of PAEs, the hydrolysis time was decreased from a previously reported time of 20 h to 10 min (80 °C). The resulting phthalic acid in the acidified hydrolysate was extracted with 600 μL of tributyl phosphate and then analyzed by high performance liquid chromatography-tandem mass spectrometry in 6 min. Parameters affecting the hydrolysis of PAEs and the extraction of phthalic acid were optimized, and the analytical method was validated. No obvious matrix effect existed in the edible oils whether an external or internal standard method was used. The detection limit was 1.0 μmol kg(-1), and the quantification limit was 1.3 μmol kg(-1). The recovery rates varied from 86 to 107% with relative standard deviations equal to or lower than 9.9% in all of the tested conditions. Twenty-six samples were analyzed, and the background corrected total PAE content was found to be in the range of

A simple sample preparation method requiring minimal organic solvents is proposed for the determination of the total phthalate content in cosmetics by high-performance liquid chromatography-tandem mass spectrometry. The hydrolysis of phthalates and purification of interfering substances were performed in a three-phase system that included an upper n-hexane phase, a middle ethanol phase, and a lower aqueous alkali solution. This three-phase system utilized an incremental purification strategy. The apolar ingredients were extracted with n-hexane, the polar pigments accumulated in the ethanol phase, and the hydrolysis product, phthalic acid, remained in the hydrolysate. Under the optimized conditions, the correlation coefficients (r) for the calibration curves were 0.998–0.999 in the range 0.60–12 mol L−1. The limit of detection was 5.1 μmol kg−1, and the limit of quantification was 9.2 μmol kg−1. The recoveries varied from 84 to 97% with RSDs equal to or lower than 11%. The intra-day and inter-day repeatability values, expressed as the relative standard deviation, were less than 8.7 and 9.8, respectively. No obvious matrix effect existed in the different cosmetics matrices. The validated method was applied for the analysis of 57 commercial cosmetic samples.

UNLABELLED This study established a new method for quantitative and qualitative determination of certain components in black rice wine, a traditional Chinese brewed wine. Specifically, we combined solid-phase extraction and high-performance liquid chromatography (HPLC) with triple quadrupole mass spectrometry (MS/MS) to determine 8 phenolic acids, 3 flavonols, and 4 anthocyanins in black rice wine. First, we clean samples with OASIS HLB cartridges and optimized extraction parameters. Next, we performed separation on a SHIM-PACK XR-ODS column (I.D. 3.0 mm × 75 mm, 2.2 μm particle size) with a gradient elution of 50% aqueous acetonitrile (V/V) and water, both containing 0.2% formic acid. We used multiple-reaction monitoring scanning for quantification, with switching electrospray ion source polarity between positive and negative modes in a single chromatographic run. We detected 15 phenolic compounds properly within 38 min under optimized conditions. Limits of detection ranged from 0.008 to 0.030 mg/L, and average recoveries ranged from 60.8 to 103.1% with relative standard deviation ≤8.6%. We validated the method and found it to be sensitive and reliable for quantifying phenolic compounds in rice wine matrices. PRACTICAL APPLICATION This study developed a new, reliable HPLC-MS/MS method for simultaneous determination of 15 bioactive components in black rice wine. This method was validated and found to be sensitive and reliable for quantifying phenolic compounds in rice wine.

A reliable and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, and AFG2), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA), fumonisin B1 (FB1), and T2-toxin in maize. The samples were first extracted using acetonitrile: water: acetic acid (79 : 20 : 1), and then further cleaned-up using OASIS HLB cartridge. Optimum conditions for the extraction and chromatographic separation were investigated. The mean recoveries of mycotoxins in spiked maize ranged from 68.3% to 94.3%. Limits of detection and quantification ranged from 0.01 to 0.64 μg/kg and from 0.03 to 2.12 μg/kg, respectively. The LC-MS/MS method has also been successfully applied to 60 maize samples, which were collected from Shaanxi Province of China. Twenty-four of the total 60 samples (40%) were contaminated with at least 1 of these 9 mycotoxins. Occurrence of mycotoxins were 6.7%, 1.7%, 3.3%, 6.7%, 1.7%, 23.3%, and 3.3% for AFB1, AFB2, OTA, ZEA, DON, FB1, and T2-toxin, respectively. The results demonstrated that the procedure was suitable for the simultaneous determination of these mycotoxins in maize matrix. Practical Application A sensitive LC-MS/MS method was developed for the simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, AFG2), OTA, DON, ZEA, FB1, and T2-toxin in maize; OASIS HLB cartridge was adopted for cleanup of mycotoxins. This method will have potential analytical applications for other cereals and can be performed for routine analysis in laboratories.